Rumination mediates associations between microaggressions and sleep quality in Black Americans: the toll of racial microstressors

Disparities in health outcomes between Black and White Americans are well-documented, including sleep quality, and disparities in sleep may lead to disparities in health over the life course. A meta-model indicates that cognitive processes may underly the connection between race and poor sleep quality, and ultimately, health disparities. That is, there are race-specific stressors that disproportionately affect Black Americans, which are associated with poor health through biological, cognitive, and behavioral mechanisms (e.g., sleep). Among these race-specific stressors is discrimination, which has been linked to poor sleep quality, and there is a body of literature connecting perseverative cognition (e.g., rumination and worry or vigilance) to poor sleep. Microaggressions, a more subtle but pervasive form of discrimination, are another race-specific stressor. Although less research has considered the connection of microaggressions to perseverative cognition, there are some studies linking microaggressions to health outcomes and sleep. Therefore, using a cross-sectional survey, we tested the following hypotheses: racism-related vigilance and rumination would mediate the relationship between discrimination and poor sleep as well as between microaggressions and poor sleep among Black Americans (N = 223; mean age = 35.77 years, 53.8% men, 86% employed, 66.8% with college degree or higher education). Results of seven parallel mediation models showed that neither rumination nor racism-related vigilance mediated a relationship between discrimination and poor sleep quality. However, rumination partially mediated relationships between the six microaggression sub-scales and poor sleep quality: there were significant indirect effects for Foreigner/Not Belonging (β = .13, SE = 0.03, 95% CI 0.08, 0.20), Criminality (β = .11, SE = 0.03, 95% CI 0.05, 0.17), Sexualization (β = .10, SE = 0.03, 95% CI 0.05, 0.17), Low-Achieving/Undesirable (β = .10, SE = 0.03, 95% CI 0.05, 0.15), Invisibility (β = .15, SE = 0.04, 95% CI 0.08, 0.23), and Environmental Invalidations (β = .15, SE = 0.04, 95% CI 0.08, 0.23). Overall, these findings indicate support for the meta-model, demonstrating a specific pathway from racial microstressors to poor sleep quality. Furthermore, these results suggest the importance of developing clinical and community approaches to address the impact of microaggressions on Black Americans' sleep quality.

Evaluating skills for psychological recovery with gunshot injury survivors in a hospital-based early intervention program

Gun violence is a serious public health problem that places surviving victims at increased risk for a variety of mental health problems, including posttraumatic stress disorder (PTSD) and depression. Recognizing that many gunshot injury survivors lack access to mental health care in the early aftermath of a shooting, there has been growing interest in the use of early, preventive mental health interventions to help prevent long-term mental health complications like PTSD as part of routine care for survivors in acute medical settings, where initial outreach to survivors may be more successful. This study evaluates clinical outcomes associated with one such early intervention-Skills for Psychological Recovery (SPR)-provided to gunshot injury survivors as part of a hospital-based early intervention program embedded in a Level 1 trauma center in the Midwestern United States. Clinic data from 100 survivors (74.0% male, 78.0% Black/African American) who received SPR were included in the present study. Results suggest that receiving SPR in the early aftermath of a shooting is associated with statistically significant reductions in both PTSD, F(1, 26.77) = 22.49, p < .001, and depression, F(1, 29.99) = 6.49, p = .016, symptoms. Outcomes did not vary as a function of either PTSD risk status or intervention delivery method (i.e., in-person, telehealth). These findings support the effectiveness and acceptability of SPR as an early intervention for gunshot injury survivors when delivered as part of a hospital-based early intervention program. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Finding benefits in a cardiac event: Direct links with positive affect and healthy dietary behaviors during cardiac rehabilitation

Benefit finding (BF) may be a coping strategy that positively influences outcomes after a stressful event, but previous studies provide an inconsistent pattern of results across several different patient populations. This study aimed to reconcile these inconsistencies by testing whether positive affect related to a cardiac event (PA) mediates the relationship between BF and healthy dietary behaviors, and whether this mediating relationship is stronger for participants high in disease severity. Participants were patients with cardiovascular disease in a cardiac rehabilitation program. Results supported partial mediation, but the interaction was not as predicted: participants low in disease severity showed a stronger relationship between BF and PA than their counterparts high in disease severity. Additionally, the PA/healthy dietary behaviors relationship was negative. Health providers may encourage patients in CR to engage in BF, but also to make thoughtful food decisions when in a positive mood, especially for patients low in disease severity.

Characterization of a Regional Childhood Obesity Prevention and Treatment System

This project characterized the system of childhood obesity-related programs and functions based on a socioecological framework within the Kansas City region to determine strengths, weaknesses, and leverage points for informing collective impact. A mixed-method approach was employed to identify and collect data ∼260 childhood obesity-related programs provided by 89 organizations. Findings indicated no major gaps in population or location served although few programs specifically focused on service to minority groups or neighborhoods. The region has many programs working within the system, yet the distribution of programs does not occur as expected throughout the dimensions of a standard socioecological model or community health system. In addition, several organizations perform certain leadership functions such as coordination, resource allocation, or monitoring, but none perform all, indicating the lack of a traditional "backbone" organization. These findings demonstrate how a region's childhood obesity prevention and treatment programs can be evaluated using a socioecological framework.

Development and Psychometric Properties of the Self-Blame Attributions for Cancer Scale

OBJECTIVES

To adapt the Cardiac Self-Blame Attributions Scale into the Self-Blame Attributions for Cancer Scale (SBAC) for use in patients with cancer and analyze its psychometric properties.

SAMPLE & SETTING

113 patients receiving radiation therapy at the University of Kansas Cancer Center.

METHODS & VARIABLES

The SBAC and other self-report measures were administered during outpatient oncology appointments for radiation therapy to establish the psychometric properties of the SBAC.

RESULTS

A two-factor structure represented behavioral and characterological self-blame attributions. Reliability estimates for each factor were excellent and evidence of convergent and discriminant validity was found, indicating support for the SBAC as a valid and reliable measure of self-blame attributions in patients with cancer.

IMPLICATIONS FOR NURSING

The SBAC may help healthcare providers, including nursing staff, to identify the self-blame patterns exhibited by patients with cancer. Future research can assess the reliability and validity of SBAC across stages of treatment and establish the predictive validity of the scale in individuals with cancer.

Scale development and psychometric properties of the Cardiac Self-Blame Attributions scale in patients with cardiovascular disease

Patients with cardiovascular disease may attribute their cardiovascular disease to their behaviors (behavioral self-blame) or to their dispositions (characterological self-blame). However, findings are mixed on the effects of behavioral self-blame and characterological self-blame on health outcomes, possibly because there are no validated, multiple-item measures. This study developed and tested an 11-item Cardiac Self-Blame Attributions scale via questionnaire data from 121 patients with cardiovascular disease. Results yielded a two-factor structure that explained 65 percent of the variance, with good reliability and discriminant validity. Findings suggest that the scale is reliable and valid and can be used to understand the cardiac attributions patients create.

Marginal Emissions Factors for Electricity Generation in the Midcontinent ISO

Environmental consequences of electricity generation are often determined using average emission factors. However, as different interventions are incrementally pursued in electricity systems, the resulting marginal change in emissions may differ from what one would predict based on system-average conditions. Here, we estimate average emission factors and marginal emission factors for CO₂, SO₂, and NO_x from fossil and nonfossil generators in the Midcontinent Independent System Operator (MISO) region during years 2007-2016. We analyze multiple spatial scales (all MISO; each of the 11 MISO states; each utility; each generator) and use MISO data to characterize differences between the two emission factors (average; marginal). We also explore temporal trends in emissions factors by hour, day, month, and year, as well as the differences that arise from including only fossil generators versus total generation. We find, for example, that marginal emission factors are generally higher during late-night and early morning compared to afternoons. Overall, in MISO, average emission factors are generally higher than marginal estimates (typical difference: ∼20%). This means that the true environmental benefit of an energy efficiency program may be ∼20% smaller than anticipated if one were to use average emissions factors. Our analysis can usefully be extended to other regions to support effective near-term technical, policy and investment decisions based on marginal rather than only average emission factors.

Marginal Emission Factors Considering Renewables: A Case Study of the U.S. Midcontinent Independent System Operator (MISO) System

Estimates of marginal emission factors (MEFs) for the electricity sector have focused on emitting sources only, assuming nonemitting renewables rarely contribute to marginal generation. However, with increased penetration and improved dispatch of renewables, this assumption may be outdated. Here, we improve the methodology to incorporate renewables in MEF estimates and demonstrate a case study for the Midcontinent Independent System Operator (MISO) system where wind has been commonly dispatched on the margin. We also illustrate spatiotemporal variations of MEFs and explore implications for energy storage technologies. Results show that because the share of renewables in MISO is still relatively low (6.34%), conventional MEFs focused on emitting sources can provide a good estimate in MISO overall, as well as in the Central and South subregions. However, in the MISO North subregion where wind provides 22.5% of grid generation, neglecting nonemitting sources can overestimate MEFs for CO₂, SO₂, and NO_x by about 30%. The application of expanded MEFs in this case also reveals heightened emission increases associated with load shifting of storage technologies. Our study highlights the importance of expanded MEFs in regions with high and growing renewables penetration, particularly as renewable energy policy seeks to incorporate demand-side technologies.

The Leakage Risk Monetization Model for Geologic CO2 Storage

We developed the Leakage Risk Monetization Model (LRiMM) which integrates simulation of CO2 leakage from geologic CO2 storage reservoirs with estimation of monetized leakage risk (MLR). Using geospatial data, LRiMM quantifies financial responsibility if leaked CO2 or brine interferes with subsurface resources, and estimates the MLR reduction achievable by remediating leaks. We demonstrate LRiMM with simulations of 30 years of injection into the Mt. Simon sandstone at two locations that differ primarily in their proximity to existing wells that could be leakage pathways. The peak MLR for the site nearest the leakage pathways ($7.5/tCO2) was 190x larger than for the farther injection site, illustrating how careful siting would minimize MLR in heavily used sedimentary basins. Our MLR projections are at least an order of magnitude below overall CO2 storage costs at well-sited locations, but some stakeholders may incur substantial costs. Reliable methods to detect and remediate leaks could further minimize MLR. For both sites, the risk of CO2 migrating to potable aquifers or reaching the atmosphere was negligible due to secondary trapping, whereby multiple impervious sedimentary layers trap CO2 that has leaked through the primary seal of the storage formation.

A pilot study of an Internet walking program and pedometer in COPD

BACKGROUND

Higher levels of physical activity are associated with better functional status, fewer hospital admissions, and lower mortality. In this pilot study, we examined the feasibility and safety of a novel program that combines a pedometer with a website to increase walking.

METHODS

27 persons with stable COPD wore the Omron HJ-720ITC pedometer and used the website for 90 days. They uploaded step-count data to the study server using their home computer and received an email each week with their individualized step-count goal. The website provided step-count feedback, education, and motivational content. Subjects participated in a monthly semi-structured interview by telephone. Subjects reported changes in medical condition by telephone or on the website. Paired T-tests assessed change in daily step counts.

RESULTS

Subjects were males, mean age 72 ± 8 years, with moderate COPD, FEV(1) 1.57 ± 0.48 L (55 ± 16% predicted). 87% and 65% reported no problems using the pedometer and website, respectively. At month 3, 96% reported it was true that they knew their step count goal every day, and 52% reported that they were able to reach their goal. 95% of participants said they would recommend the walking program to another person with COPD. Eight subjects experienced breathing problems unrelated to the intervention. In 24 subjects with step counts at baseline and month 3, there was a significant increase of 1263 steps per day (approximately 1.0 km), p = 0.0054.

CONCLUSIONS

The use of a website and pedometer was feasible and safe, and persons increased their daily walking.

A web-based pedometer programme in women with a recent history of gestational diabetes

AIMS

Women with remote histories of gestational diabetes mellitus can reduce their diabetes risk through lifestyle changes, but the effectiveness of interventions in women with more recent histories of gestational diabetes has not been reported. Therefore, we conducted a pilot study of a low-intensity web-based pedometer programme targeting glucose intolerance among women with recent gestational diabetes.

METHODS

Women with a gestational diabetes delivery within the past 3 years were randomized to a 13-week intervention consisting of a structured web-based pedometer programme which gave personalized steps-per-week goals, pedometers and education regarding lifestyle modification, or to a letter about diabetes risk reduction and screening after delivery for gestational diabetes (control condition). The main outcome measures were change in fasting plasma glucose and 2-h glucose levels on a 75-g oral glucose tolerance test between baseline and 13-week follow-up. Weight was a secondary outcome and behavioural constructs (self-efficacy, social support, risk perception) were also assessed.

RESULTS

Forty-nine women were enrolled. At 13-week follow-up, women randomized to the intervention did not have significant changes in behavioural constructs, physical activity or anthropometrics compared with women in the control group. Changes in fasting plasma glucose (-0.046 mmol/l vs. 0.038 mmol/l, P = 0.65), 2-h glucose values (-0.48 mmol/l vs. -0.42 mmol/l, P = 0.91) and weight (-0.14 kg vs. -1.5 kg, P = 0.13) were similar between the control and intervention groups, respectively.

CONCLUSIONS

Structured web-based education utilizing pedometers is feasible although uptake may be low. Such programmes may need to be supplemented with additional measures in order to be effective for reduction of diabetes risk.

Vehicle emissions during children's school commuting: impacts of education policy

We explore how school policies influence the environmental impacts of school commutes. Our research is motivated by increased interest in school choice policies (in part because of the U.S. "No Child Left Behind" Act) and in reducing bus service to address recent budget shortfalls. Our analysis employs two samples of elementary-age children, age 5-12: a travel survey (n = 1246 respondents) and a school enrollment data set (n = 19,655 students). Multinomial logistic regression modeled the determinants of travel mode (automobile, school bus, and walking; n = 803 students meeting selection criteria). Travel distance has the single greatest effect on travel mode, though school choice, trip direction (to- or from-school), and grade play a role. Several policies were investigated quantitatively to predict the impact on school travel, vehicle emissions, and costs. We find that eliminating district-wide school choice (i.e., returning to a system with neighborhood schools only) would have significant impacts on transport modes and emissions, whereas in many cases proposed shifts in school choice and bus-provision policies would have only modest impacts. Policies such as school choice and school siting may conflict with the goal of increasing rates of active (i.e., nonmotorized) school commuting. Policies that curtail bus usage may reduce bus emissions but yield even larger increases in private-vehicle emissions. Our findings underscore the need to critically evaluate transportation-related environmental and health impacts of currently proposed changes in school policy.

Wind deployment in the United States: states, resources, policy, and discourse

A transformation in the way the United States produces and uses energy is needed to achieve greenhouse gas reduction targets for climate change mitigation. Wind power is an important low-carbon technology and the most rapidly growing renewable energy technology in the U.S. Despite recent advances in wind deployment, significant state-by-state variation in wind power distribution cannot be explained solely by wind resource patterns nor by state policy. Other factors embedded within the state-level socio-political context also contribute to wind deployment patterns. We explore this socio-political context in four U.S. states by integrating multiple research methods. Through comparative state-level analysis of the energy system, energy policy, and public discourse as represented in the media, we examine variation in the context for wind deployment in Massachusetts, Minnesota, Montana, and Texas. Our results demonstrate that these states have different patterns of wind deployment, are engaged in different debates about wind power, and appear to frame the risks and benefits of wind power in different ways. This comparative assessment highlights the complex variation of the state-level socio-political context and contributes depth to our understanding of energy technology deployment processes, decision-making, and outcomes.

Reducing motor vehicle greenhouse gas emissions in a non-California state: a case study of Minnesota

Approaches for reducing greenhouse gas (GHG) emissions from motor vehicles include more-efficient vehicles, lower-carbon fuels, and reducing vehicle-kilometers traveled (VKT). Many U.S. states are considering steps to reduce emissions through actions in one or more of these areas. We model several technology and policy options for reducing GHGs from motor vehicles in Minnesota. Considerable analysis of transportation GHGs has been done for California, which has a large population and vehicle fleet and can enact unique emissions regulations; Minnesota represents a more typical state with respect to many demographic and transportation parameters. We conclude that Minnesota has a viable approach to meeting its stated GHG reduction targets (15% by 2015 and 30% by 2025, relative to year 2005) only if advancements are made in all three areas-vehicle efficiency, carbon content of fuels, and VKT. If policies focus on only one or two areas, potential improvements may be negated by backsliding in another area (e.g., increasing VKT offsetting improvements in vehicle efficiency).

Regulating geologic sequestration in the United States: early rules take divergent approaches

Regulations for geological sequestration (GS) of carbon dioxide (CO2) have been adopted in the state of Washington and proposed by the state of Kansas and the U.S. Environmental Protection Agency (EPA) Underground Injection Control (UIC) Program. These three sets of rules take significantly different approaches to regulating GS of CO2. This paper compares these rules, focusing on elements where their differences highlight the choices that must be made to create a regulatory framework for GS in the United States. Consensus is emerging in some areas, but there is still substantial disagreement regarding the allowable composition of the CO2 stream, the size of the area of review, reservoir performance goals, and management of risks other than those to groundwater. Gaps include issues related to ownership of subsurface pore space, greenhouse gas accounting, and long-term stewardship. The divergent approaches of these rules raise two overarching questions: (1) Should policy makers create GS regulations by modifying and supplementing UIC rules or through new enabling legislation? (2) What should be the relative roles of state and federal governments in GS regulation? We outline trade-offs between the consistency and coordination that federal involvement could offer and the reality that states need to be heavily involved with implementation of GS regulations. We conclude that federal involvement above and beyond the proposed EPA Class VI rules is needed to create effective GS regulation in the United States.

Reducing greenhouse gas emissions for climate stabilization: framing regional options

The Intergovernmental Panel on Climate Change (IPCC) has stated that stabilizing atmospheric CO2 concentrations will require reduction of global greenhouse gas (GHG) emissions by as much as 80% by 2050. Subnational efforts to cut emissions will inform policy development nationally and globally. We projected GHG mitigation strategies for Minnesota, which has adopted a strategic goal of 80% emissions reduction by 2050. A portfolio of conservation strategies, including electricity conservation, increased vehicle fleet fuel efficiency, and reduced vehicle miles traveled, is likely the most cost-effective option for Minnesota and could reduce emissions by 18% below 2005 levels. An 80% GHG reduction would require complete decarbonization of the electricity and transportation sectors, combined with carbon capture and sequestration at power plants, or deep cuts in other relatively more intransigent GHG-emitting sectors. In order to achieve ambitious GHG reduction goals, policymakers should promote aggressive conservation efforts, which would probably have negative net costs, while phasing in alternative fuels to replace coal and motor gasoline over the long-term.

Environmental bonds and the challenge of long-term carbon sequestration

The potential to capture carbon from industrial sources and dispose of it for the long-term, known as carbon capture and sequestration (CCS), is widely recognized as an important option to reduce atmospheric carbon dioxide emissions. Specifically, CCS has the potential to provide emissions cuts sufficient to stabilize greenhouse gas levels, while still allowing for the continued use of fossil fuels. In addition, CCS is both technologically-feasible and commercially viable compared with alternatives with the same emissions profile. Although the concept appears to be solid from a technical perspective, initial public perceptions of the technology are uncertain. Moreover, little attention has been paid to developing an understanding of the social and political institutional infrastructure necessary to implement CCS projects. In this paper we explore a particularly dicey issue--how to ensure adequate long-term monitoring and maintenance of the carbon sequestration sites. Bonding mechanisms have been suggested as a potential mechanism to reduce these problems (where bonding refers to financial instruments used to ensure regulatory or contractual commitments). Such mechanisms have been successfully applied in a number of settings (e.g., to ensure court appearances, completion of construction projects, and payment of taxes). The paper examines the use of bonding to address environmental problems and looks at its possible application to nascent CCS projects. We also present evidence on the use of bonding for other projects involving deep underground injection of materials for the purpose of long-term storage or disposal.

Regulating the geological sequestration of CO2

Governments worldwide should provide incentives for initial large-scale GS projects to help build the knowledge base for a mature, internationally harmonized GS regulatory framework. Health, safety, and environmental risks of these early projects can be managed through modifications of existing regulations in the EU, Australia, Canada, and the U.S. An institutional mechanism, such as the proposed Federal Carbon Sequestration Commission in the U.S., should gather data from these early projects and combine them with factors such as GS industrial organization and climate regime requirements to create an efficient and adaptive regulatory framework suited to large-scale deployment. Mechanisms to structure long-term liability and fund long-term postclosure care must be developed, most likely at the national level, to equitably balance the risks and benefits of this important climate change mitigation technology. We need to do this right. During the initial field experiences, a single major accident, resulting from inadequate regulatory oversight, anywhere in the world, could seriously endanger the future viability of GS. That, in turn, could make it next to impossible to achieve the needed dramatic global reductions in CO2 emissions over the next several decades. We also need to do it quickly. Emissions are going up, the climate is changing, and impacts are growing. The need for safe and effective CO2 capture with deep GS is urgent.

Research for deployment: incorporating risk, regulation, and liability for carbon capture and sequestration

Carbon capture and sequestration (CCS) has the potential to enable deep reductions in global carbon dioxide (CO2) emissions, however this promise can only be fulfilled with large-scale deployment. For this to happen, CCS must be successfully embedded into a larger legal and regulatory context, and any potential risks must be effectively managed. We developed a list of outstanding research and technical questions driven by the demands of the regulatory and legal systems for the geologic sequestration (GS) component of CCS. We then looked at case studies that bound uncertainty within two of the research themes that emerge. These case studies, on surface leakage from abandoned wells and groundwater quality impacts from metals mobilization, illustrate how research can inform decision makers on issues of policy, regulatory need, and legal considerations. A central challenge is to ensure that the research program supports development of general regulatory and legal frameworks, and also the development of geological, geophysical, geochemical, and modeling methods necessary for effective GS site monitoring and verification (M&V) protocols, as well as mitigation and remediation plans. If large-scale deployment of GS is to occur in a manner that adequately protects human and ecological health and does not discourage private investment, strengthening the scientific underpinnings of regulatory and legal decision-making is crucial.

Regulating the ultimate sink: managing the risks of geologic CO2 storage

The geologic storage (GS) of carbon dioxide (CO2) is emerging as an important tool for managing carbon. While this Journal recently published an excellent review of GS technology (Bruant, R. G.; Guswa, A. J.; Celia, M. A.; Peters, C. A. Environ. Sci. Technol. 2002, 36, 240A-245A), few studies have explored the regulatory environment for GS or have compared it with current underground injection experience. We review the risks and regulatory history of deep underground injection on the U.S. mainland and surrounding continental shelf. Our treatment is selective, focusing on the technical and regulatory aspects that are most likely to be important in assessing and managing the risks of GS. We also describe current underground injection activities and explore how these are now regulated.

Life cycle inventory for municipal solid waste management. Part 2: MSW management scenarios and modeling

Evaluating the environmental performance of municipal solid waste management options is a complex task. Part 1 of this study presents the municipal solid waste management program of the Pamplona Region in Spain and explores the operational, economic, and environmental factors of the program. In Part 2, alternative waste management scenarios that include the selective collection of organic material and composting are illustrated. The use of a Life Cycle Inventory model for waste management allows for the comparison of the environmental burdens of the different scenarios. This use of a Life Cycle Inventory model for solid waste management lets program managers and decision makers include energy use, final solid waste, and Greenhouse gas emissions in the decision making process. Additionally, the different management scenarios are evaluated on their ability to fulfil Pamplona regional objectives and meet European Packaging and Landfill Directive targets.

Life cycle inventory for municipal solid waste management

Evaluating the environmental performance of municipal solid waste management options is a complex task. Part 1 of this study presents the municipal solid waste management program of the Pamplona Region in Spain, exploring the institutional, operational and economic factors of the program. In Part 2, alternative waste management scenarios that include the selective collection of organic material and composting are illustrated. The use of a Life Cycle Inventory model for waste management allows for the comparison of the environmental burdens of the different scenarios. This use of a Life Cycle Inventory model for solid waste management lets program managers and decision makers include energy use, final solid waste, and Greenhouse gas emissions in the decision making process. Additionally, the different management scenarios are evaluated on their ability to fulfil Pamplona regional objectives and meet European Packaging and Landfill Directive targets.

Dietary nickel improves male broiler (Gallus domesticus) bone strength

The effects of dietary nickel (0, 25, 50, 75, 100, and 150 mg/kg) on the bone strength characteristics and performance parameters of male broilers were investigated. Broilers were housed in either cages or floor pens. At 6 wk of age, the shear fracture energy of the tibia from the caged birds increased when the basal diet was supplemented with 25 mg of dietary nickel per kilogram of feed. The shear force, stress, and fracture energy of the radius from the caged birds also increased at 25 mg/kg nickel. Dietary nickel had no effect on bird body weight, but the caged broilers (2,161 g) were heavier than the floor birds (2,005 g). Nickel had no effect on the strength characteristics of the tibia from the floor birds. Percent tibia bone ash, a measure of bone density, was not influenced by dietary nickel, but the tibia ash of the floor birds was greater than that of the caged birds. Overall, the data indicates that adding 25 mg/kg of dietary nickel to a poultry diet will have a positive influence on bone strength characteristics and performance.

Realities of practice. Engaging parents and GPs in developing clinical practice guidelines

OBJECTIVE

To integrate evidence based medicine with the experience and expectations of consumers and GPs in the development of clinical practice guidelines for acute respiratory infections (ARI) in young children.

METHOD

Focus groups and workshops were held with 21 GPs and 27 patients of young children involved in a 2 year randomised controlled trial.

RESULTS

The acceptability of the guideline development process for participants was determined. Barriers were identified which would impede clinical change, including: inadequate time; lack of knowledge; fear of patient dissatisfaction; and fear of poor health outcome.

CONCLUSION

This paper details a process of guideline development that addresses the realities of general practice in Australia and the concerns of consumers. We identified potential barriers to change and integrated intervention strategies with the evidence to produce realistic clinical practice guidelines.

Antibiotic resistance in Streptococcus pneumoniae isolated from children

OBJECTIVE

To determine the level of antibiotic resistance in pneumoniae (S. pneumoniae) isolated from nasal swabs of healthy children.

METHOD

Cross-sectional community survey.

SETTING

Survey was undertaken in general practice settings in Canberra during March and April 1998.

SUBJECTS

Four hundred and sixty-one children under 3 years of age enrolled in general practice trial of clinical practice guidelines for antibiotic use.

OUTCOME MEASURES

Resistance to penicillin, erythromycin, co-trimoxazole, tetracycline, chloramphenicol and cefotaxime among the isolates of S. pneumoniae.

RESULTS

A total of 461 nasal swabs were collected and S. pneumoniae was isolated from 171 (37.1%). Penicillin resistance was found in 12.3% of these isolates, with high level resistance in 0.6%. Resistance rates were higher for cotrimoxazole (44.4%) and erythromycin (18.1%) than for penicillin. Multidrug resistance was found in 19% of these isolates. There was a significant association between the attendance at a day care centre and carriage of pneumococcus (53% vs 32%, odds ratio (OR) 2.4, 95% confidence interval (CI) 1.5-3.7, P < 0.001). Children who attended day care centers and had received antibiotics during the 4 months prior to swab collection were three times more likely to carry an antibiotic-resistant isolate than children who had neither attended a day care centre nor received antibiotics (68% vs 40%, OR 3.1, 95% CI 1.2-8.4, P = 0.02).

CONCLUSION

The level of antibiotic resistance in pneumococci from healthy children was of concern. Carriage of pneumococcus was significantly higher in children who attended a day care centre. Resistance was significantly correlated with antibiotic use in combination with day-care attendance. These findings warrant more judicious use of antibiotics in children.

Epidermal growth factor inhibits carbachol-stimulated canine parietal cell function via protein kinase C

BACKGROUND & AIMS

Epidermal growth factor (EGF) inhibits secretagogue-stimulated gastric acid secretion via an EGF receptor located on parietal cells. The aim of this study was to examine whether this growth factor inhibited carbachol-stimulated acid secretion through a protein kinase C-dependent mechanism.

METHODS

The effect of EGF on carbachol-stimulated aminopyrine uptake, inositol trisphosphate formation, and intracellular Ca2+ ([Ca2+]i) in purified cultured parietal cells was studied. The ability of protein kinase A and C inhibitors to alter the inhibitory action of EGF was assessed. EGF-mediated translocation and activation of protein kinase C in parietal cells were determined.

RESULTS

EGF dose dependently inhibited carbachol-stimulated aminopyrine uptake in a pertussis toxin-insensitive, genistein (tyrosine kinase inhibitor)--sensitive manner, with a maximal inhibitory effect (37.5% +/- 6.8%) achieved at 10(-7) mol/L. EGF did not significantly inhibit carbachol-stimulated inositol trisphosphate formation and did not alter the initial transient increase or sustained plateau in [Ca2+]i stimulated by this secretagogue. The protein kinase C inhibitors H-7 and staurosporine dose dependently reversed the inhibitory action of EGF, whereas H-89 (protein kinase A inhibitor) failed to alter the effect of EGF. EGF pretreatment increased the translocation of alpha and beta 1 isoforms of protein kinase C and stimulated kinase activity in parietal cells. EGF did not down-regulate the parietal cell muscarinic receptor.

CONCLUSIONS

The inhibitory action of EGF on carbachol-stimulated parietal cell activity seems to involve protein kinase C.

The rate of thermal inactivation of Torpedo acetylcholinesterase is not reduced in the C231S mutant

The rate of thermal inactivation of Torpedo AChE at pH 8.5 was increased by the sulfhydryl reagent 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB). At 30 degrees C or 37 degrees C, inactivation rates with 0.3 mM DTNB increased about 5-fold for the wild-type enzyme and for two site-specific mutants, D72S and V129R. The reversible active site inhibitor, ambenonium, completely stabilized the wild type enzyme and partially stabilized the D72S mutant. However, ambenonium did not protect against the destabilization introduced by DTNB, which still accelerated inactivation of D72S 5-fold. When the only free sulfhydryl group in AChE was removed by replacing cysteine 231 with serine, increased rates of thermal inactivation were observed. The inactivation rate increased by a factor of 2 to 3 for the single mutant (C231S) and by a factor of 5 for the double mutant V129R/C231S. Even in the C231S mutants, DTNB still had an additional effect. It increased the inactivation rate for C231S and V129R/C231 by a factor of about 1.5 to 3 beyond the rates seen in the absence of DTNB. Therefore, at least part of the destabilization seen with DTNB in enzymes that retain C231 does not involve reaction of DTNB with C231.

Fasciculin 2 binds to the peripheral site on acetylcholinesterase and inhibits substrate hydrolysis by slowing a step involving proton transfer during enzyme acylation

The acetylcholinesterase active site consists of a gorge 20 A deep that is lined with aromatic residues. A serine residue near the base of the gorge defines an acylation site where an acyl enzyme intermediate is formed during the hydrolysis of ester substrates. Residues near the entrance to the gorge comprise a peripheral site where inhibitors like propidium and fasciculin 2, a snake neurotoxin, bind and interfere with catalysis. We report here the association and dissociation rate constants for fasciculin 2 interaction with the human enzyme in the presence of ligands that bind to either the peripheral site or the acylation site. These kinetic data confirmed that propidium is strictly competitive with fasciculin 2 for binding to the peripheral site. In contrast, edrophonium, N-methylacridinium, and butyrylthiocholine bound to the acylation site and formed ternary complexes with the fasciculin 2-bound enzyme in which their affinities were reduced by about an order of magnitude from their affinities in the free enzyme. Steady state analysis of the inhibition of substrate hydrolysis by fasciculin 2 revealed that the ternary complexes had residual activity. For acetylthiocholine and phenyl acetate, saturating amounts of the toxin reduced the first-order rate constant kcat to 0.5-2% and the second-order rate constant kcat/Kapp to 0.2-2% of their values with the uninhibited enzyme. To address whether fasciculin 2 inhibition primarily involved steric blockade of the active site or conformational interaction with the acylation site, deuterium oxide isotope effects on these kinetic parameters were measured. The isotope effect on kcat/Kapp increased for both substrates when fasciculin 2 was bound to the enzyme, indicating that fasciculin 2 acts predominantly by altering the conformation of the active site in the ternary complex so that steps involving proton transfer during enzyme acylation are slowed.

Regulatory mechanism of human factor IX gene: protein binding at the Leyden-specific region

Hemophilia B-Leyden is characterized by the gradual amelioration of bleeding after the onset of puberty. All Leyden phenotype mutations found to date lie within the Leyden-specific region, which spans roughly nt-40 to +20 in the 5' end of the human factor IX gene. With HepG2 cell nuclear extracts, the Leyden-specific region and its immediate neighboring region of the normal factor IX gene showed five DNase I footprints: FP-I (nt +4 to +19), FP-II (nt -16 to -3), FP-III (nt -27 to -19), FP-IV (nt -67 to -49), and FP-V (nt -99 to -77). Protein binding affinities of short oligonucleotides containing sequences of FP-I, FP-II, or FP-III were substantially reduced in the presence of Leyden phenotype mutations in these areas, correlating well with the negative effects of these mutations on factor IX gene expression. A Leyden phenotype mutation at nt -20 (T to A) caused a loss of both footprints FP-III and FP-II but generated a new footprint, FP-III' (nt -34 to -23), partially overlapping with FP-III, indicating mutation-dependent competitive protein binding at these sites. Although the FP-III' area contains an androgen responsive element-like sequence, the nuclear protein that binds at FP-III' is not androgen receptor. The protein was not recognized by anti-androgen receptor antibody and, furthermore, was present not only in liver but also in both androgen receptor-positive and androgen receptor-negative cells in electrophoretic mobility shift assays. The nuclear concentration of this protein increased significantly upon treatment of the HepG2 cells with testosterone. Its binding affinity to an oligonucleotide (-32sub) containing the FP-III' sequence was greatly reduced in the presence of exogenous androgen receptor, suggesting a possible interaction of this protein with androgen receptor. The affinities of both this protein and a protein which binds to FP-III (presumably HNF-4) to -32sub with a mutation at nt -26 were grossly lowered. These findings suggest that the amelioration of hemophilia B-Leyden with a mutation at nt -20 after puberty involves binding of a specific non-androgen receptor nuclear protein at FP-III' and it is able to substitute for the function of a protein bound at FP-III in the normal gene optimally through its elevated interaction with androgen receptor upon a surge of testosterone.(ABSTRACT TRUNCATED AT 400 WORDS)

The effects of excess nitrogen deposition on young Norway spruce trees. Part II the vegetation

The effects of wet-deposited nitrogen on soil acidification and the health of Norway spruce were investigated in a pot experiment using an open-air spray/drip system. Nitrogen was applied as ammonium ((NH(4))(2)SO(4)) or nitrate (HNO(3)/NaNO(3)) in simulated rain to either the soil or the foliage. Symptoms of forest decline as observed in the field were not reproduced, and there was no evidence of direct toxicity. Treatments did, however, have significant effects on tree nutrition. Both NH(+)(4) and NO(-)(3) treatment applied to the foliage lowered foliar K concentrations. NH(+)(4) to a greater extent. Soil-applied NH(+)(4) reduced foliar Mg concentrations and increased foliar Al and Fe. Soil-applied NO(-)(3) significantly reduced foliar P concentrations, and at high doses prevented the alleviation of P deficiency by fertiliser. These effects could be important in some field situations. Ammonium deposition is predicted to be more damaging than nitrate deposition, although the latter may be critical for forests where P status is marginal, such as in parts of the British uplands.

The effects of excess nitrogen deposition on young Norway spruce trees. Part I the soil

The effects of wet-deposited nitrogen on soil acidification and the health of Norway spruce were investigated in a pot experiment using an open-air spray/drip system. Nitrogen was applied as ammonium ((NH(4))(2)SO(4)) or nitrate (HNO(3)/NaNO(3)) in simulated rain to either the soil or the foliage for a period of two years five months. Symptoms of forest decline were not reproduced. Adverse effects relating to soil acidification and N saturation were observed and depended on the chemical form of N. The plant-soil system absorbed most of the soil-applied NH(+)(4) at doses of up to 65 kgN ha(-1) year(-1) but only 54% at a dose of 125 kgN ha(-1) year(-1). About 60% of soil-applied NO(-)(3) was absorbed in all treatments. Ammonium treatments acidified the soil, increased base cation leaching, and mobilised acidic cations. Nitrification was not the major source of acidity, however. Nitrate inputs increased soil pH. Critical loads calculated using current criteria were 60-120 and 30-60 kgN ha(-1) year(-1) for ammonium and nitrate, respectively. Ammonium is more likely to damage forest ecosystems, however, illustrating the need for care in the definition of critical loads.

Epidermal growth factor and transforming growth factor-alpha directly inhibit parietal cell function through a similar mechanism

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) are naturally occurring peptides which are present throughout the gastrointestinal tract and are capable of inhibiting gastric acid secretion. Although previous studies have suggested that TGF-alpha may serve as an autocrine factor regulating parietal cell function, the cellular mechanisms by which it exerts its inhibitory action have not been fully elucidated. In addition, no systematic comparison has been undertaken of the effects of EGF and TGF-alpha on parietal cell function. The aims of the present studies were to compare the actions of EGF and TGF-alpha on basal and stimulated acid secretion by isolated rabbit parietal cells and to elucidate the intracellular mechanisms by which these growth factors inhibit acid secretion stimulated by agents that activate the adenylate cyclase and cyclic AMP second messenger system. Although EGF and TGF-alpha did not alter basal parietal cell function, they both inhibited histamine-stimulated [14C]aminopyrine accumulation in a identical time- and dose-dependent fashion. The maximal effect of approximately 40% inhibition for histamine-stimulated action was achieved with concentrations of 10(-6) M for both EGF and TGF-alpha. The inhibitory effect of EGF and TGF-alpha appeared to be at the postreceptor level as neither growth factor significantly altered binding of histamine to its receptor (H2) on parietal cells. Consistent with this postulated mechanism of action, both EGF and TGF-alpha dose-dependently inhibited forskolin-stimulated aminopyrine uptake with IC50 similar to those required for inhibiting the stimulatory effect of histamine. Of note, neither growth factor inhibited parietal cell activity stimulated by dibutyryl cyclic AMP.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of T lymphocyte responses during primary infection with human immunodeficiency virus

The present study was undertaken to determine T cell response to primary human immunodeficiency virus (HIV) infection. No significant difference in T cell subsets was found between subjects who later seroconverted and a group of controls. Six subjects had multiple enumerations of T cell subsets done at the time of seroconversion. Initially, total lymphocyte and T cell subset counts were reduced. An inversion of the CD4+:CD8+ ratio due to a rise in the level of CD8+ cells was found later, followed by an appreciable increase in the number of CD8+ cells and further inversion of the CD4+:CD8+ ratio. Finally, the CD8+ cell count returned toward normal but remained higher than the CD4+ cell count; the inverted ratio was maintained. Lymphocyte hyporesponsiveness to mitogens and antigens was found during the seroconversion illness in one subject. In three of five subjects for whom data were available, an increase in the absolute number of CD8+ cells followed a decrease in the serum HIV antigen level.

Excess nitrogen deposition: issues for consideration

This paper briefly reviews some major mechanisms by which deposition of inorganic N compounds from the atmosphere could be damaging forest and natural ecosystems. Twelve issues which needed further discussion or research were identified. These were: has N deposition increased; what is a N-saturated ecosystem; can the time of onset of N saturation be predicted; can fertiliser experiments simulate the effects of atmospheric deposition; are there relationships between N input and N leaching; is N deposition leading to acidification; does high N input lead to toxicity symptoms in trees; does N input increase tree susceptibility to stress; does N input induce nutrient deficiency; does increasing N affect natural plant communities; what are the effects on aquatic ecosystems; can a 'critical load' for protection of ecosystems be defined? There is a brief critical discussion of each issue. It is concluded that there is not enough understanding of ecosystem function to define a critical load objectively, but that limits can be defined for some ecosystems.

HPLC analysis of putative amino acid neurotransmitters released from primary cerebellar cultures

An HPLC method is described that measures amino acids (putative neurotransmitters and/or neuromodulators) released from primary, dissociated cerebellar cells maintained in monolayer culture. Precolumn derivatization with phenylisothiocyanate, followed by reverse phase chromatography with UV detection was used to quantitate the phenylcarbamyl amino acid derivatives in a chemically defined medium. Quantitation was linear, reproducible and sensitive to one picomole. This method is useful for the measurement of putative neurotransmitters GABA, glutamate, aspartate, taurine and adenosine, and can easily be modified to analyze other amino acids in physiological samples.

Should nagarse be used during the isolation of brain mitochondria?

When nagarse is used to isolate brain mitochondria, a proportion of the nagarse stays associated with the mitochondrial fraction. This results in no detrimental affect on the respiratory activities. The nagarse is active in the presence of 2.3% sodium dodecyl sulfate and when samples are prepared for sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, the nagarse degrades a substantial amount of the mitochondrial proteins.

9-(1-3-Dihydroxy-2-propoxymethyl)guanine prevents death but not immunity in murine cytomegalovirus-infected normal and immunosuppressed BALB/c mice

Immunosuppressed (from treatment with cortisone acetate and anti-thymocyte globulin) and control adult female BALB/c mice, latently infected with murine cytomegalovirus (MCMV) or lethally challenged (10(6) PFU) with MCMV intraperitoneally, were treated with 9-(1-3-dihydroxy-2-propoxymethyl)guanine (DHPG) intraperitoneally. A dose of 3 mg/kg reduced mortality by 50% in lethally challenged normal mice; 10 mg/kg was required in immunosuppressed mice. When 15 mg/kg was given, the onset of treatment could be delayed for 64 h after lethal challenge. DHPG did not prevent the establishment of latent MCMV infection or immunosuppression-induced reactivation. The antibody titer to MCMV in DHPG-treated mice which survived lethal challenge was 41 (reciprocal of geometric mean) 4 to 5 weeks after inoculation; such mice survived a second lethal challenge. When antiserum treatment was begun 64 h and DHPG was begun 72 h after a lethal challenge, most mice survived; most did not when either treatment alone was begun at those times. In summary, DHPG effectively treated lethal MCMV infection even in immunosuppressed mice and even when treatment onset was delayed for 64 h. Treatment did not alter the establishment or reactivation of latent infections or the induction of effective immunity. The administration of DHPG coupled with antiserum treatment may be even more effective than the administration of either alone.

The management of late radiation-induced rectal injury after treatment of carcinoma of the uterus

Sixty-one of 1,418 (4.3 per cent) patients treated with radiation for carcinoma of the uterus from 1963 to 1983 had significant radiation-induced complications of the intestine develop which required a surgical opinion considering further management. Ninety-three per cent of these complications involved the rectum. Florid proctitis resolved within two years of onset in 33 per cent of the patients who were managed conservatively while 22 per cent of the patients died of disseminated disease within the same time period. Surgical treatment was eventually necessary in 39 per cent of the patients who were initially treated conservatively for radiation induced proctitis. Rectal excision with coloanal sleeve anastomosis produced a satisfactory result in eight of 11 patients with severe radiation injury involving the rectum. The incidence of radiation-induced and malignant rectovaginal fistula were similar (1 per cent), but disease-induced symptoms tended to occur earlier after primary treatment (a median of eight months) compared with radiation-induced symptoms (a median of 16 months).